UNIVERSITY   OF   CALIFORNIA 

COLLEGE   OF   AGRICULTURE 

AGRICULTURAL    EXPERIMENT   STATION 

BERKELEY,  CALIFORNIA 

CIRCULAR  292 
June,  1925. 

ALKALI  SOILS 

ORIGIN,  EXAMINATION,  AND  MANAGEMENT 

By  P.  L.  HIBBAKD* 


Considerable  areas  of  productive  soils  are  still  in  the  process  of 
being  injured  or  ruined  by  alkali,  with  consequent  great  economic  loss. 
Very  much  of  this  loss  could  be  avoided  by  proper  handling  of  the  soil 
and  irrigation  water  by  known  methods.  In  some  cases,  soils  which 
are  now  of  little  use  on  account  of  alkali  may  be  made  to  produce  much 
more  abundantly  by  good  management,  including  some  not  very 
expensive  treatment. 

The  purpose  of  this  circular  is  to  present  in  brief  form  the  best 
available  information  on  the  subject  of  alkali  soils  in  respect  to  origin, 
nature,  effects,  examination,  treatment,  and  cropping.  The  reader  may 
observe  a  lack  of  the  specific  or  definite  statements  which  he  would 
prefer  to  the  somewhat  general  statements  that  are  made  in  several 
places  in  this  circular.  The  reason  is  that  definite  and  reliable  informa- 
tion in  regard  to  many  points  is  not  yet  available,  so  that  only  some- 
what generalized  statements  are  now  possible.  The  purpose  is  to 
restate  the  older  views  as  modified  by  recent  investigations  carried  on 
in  California  and  elsewhere. 

That  prevention  is  cheaper  than  cure  is  most  emphatically  true  of 
alkali  soils.  To  prevent  further  injury  to  good  soils  by  alkali  should 
be  considered  by  every  public  official  who  has  any  authority  in  such 
matters,  as  one  of  his  most  important  duties.  Likewise,  every  farmer 
should  try  to  manage  his  land  in  such  manner  as  to  prevent  further 
spread  of  alkali. 


*  Grateful  acknowledgment  is  hereby  expressed  to  the  several  members  of 
the  staff,  and  in  particular  to  Professors  Hoagland,  Kelley,  and  Burd,  who  have 
aided  materially  in  the  preparation  of  the  manuscript  for  this  circular  by  their 
kindly  criticisms  and  helpful  suggestions. 


2  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

1.  What  is  Alkali? 

As  commonly  used  the  word  ' '  alkali ' '  has  no  precise  meaning.  In 
order  to  promote  clearness  in  the  present  discussion  ' '  alkali ' '  is  defined 
as  follows :  White  alkali  consists  of  one  or  more  of  the  non-alkaline 
salts  of  sodium,  such  as  the  chloride,  the  sulfate,  or  the  nitrate.  Black 
alkali  consists  of  the  truly  alkaline  salts  of  sodium,  namely,  the  bicar- 
bonate, known  as  baking  soda,  and  the  carbonate,  known  as  sal  soda, 
Occasionally  one  or  more  of  the  corresponding  compounds  of  calcium 
or  magnesium  may  be  spoken  of  as  alkali. 

2.  What  is  the  Origin  or  Source  of  Alkali? 

All  forms  of  alkali  are  derived  primarily  from  the  original  rocks. 
Most  soils  consist  largely  of  pulverized  and  somewhat  decomposed  rock 
and  therefore  are  potential  sources  of  alkali.  When  the  rocks  are 
decomposed  by  weathering,  the  various  forms  of  alkali  are  set  free. 
All  forms  of  alkali  are  easily  soluble  in  water.  Consequently  if  the 
rainfall  is  sufficient,  the  alkali  coming  from  decomposition  of  rock 
material  is  carried  away  into  the  rivers,  thence  to  the  ocean,  or  into 
some  inland  lake. 

During  past  times,  parts  of  the  ocean  were  separated  from  the  main 
body  of  water  by  changes  in  elevation  of  portions  of  the  land,  and  have 
dried  up.  In  this  way,  salt  beds  and  alkali  deposits  were  formed. 
These  may  now  lie  far  below  the  surface  of  the  ground.  When  water  is 
drawn  from  such  places,  it  is  found  to  contain  alkali.  If  this  water 
is  used  for  irrigation,  the  salts  are  deposited  on  the  ground,  thus 
producing  an  alkali  soil. 

In  arid  countries,  there  is  not  enough  rain  to  wash  away  the  salts 
which  are  slowly  being  formed  in  the  body  of  the  soil  itself  by  decom- 
position of  the  rock  fragments.  When  such  land  is  irrigated  copiously, 
without  adequate  drainage,  the  water  table  is  very  likely  to  rise  toward 
the  surface  and  bring  up  with  it  most  of  the  salts  from  the  whole  body 
of  soil.  In  this  way,  the  salts  which  were  formerly  distributed  through 
fifty  feet  of  soil  may  be  concentrated  in  the  few  feet  at  the  top  where 
evaporation  from  the  surface  will  cause  them  to  appear  as  an  alkali 
crust.  Briefly,  then,  alkali  originates  through  decay  of  the  original 
rocks  and  is  then  brought  to  the  surface  of  the  land  by  the  agency  of 
water.  Evidently  if  good  irrigating  water  is  properly  and  not  exces- 
sively used,  there  will  be  no  alkali  problem  on  land  not  already  contain- 
ing alkali — provided,  of  course,  that  the  drainage  is  good. 


Cmc.  292]  ALKALI   SOILS  3 

3.  What  is  the  Difference  Between  White  and  Black  Alkali? 

White  alkali  consists  of  the  neutral  salts,  chiefly  sodium  chloride 
and  sulfate,  which  are  not  caustic  or  corrosive  and  do  not  defiocculate 
the  soil.*  Black  alkali  consists  of  the  bicarbonate  and  the  carbonate  of 
sodium  which  are  truly  alkaline  and  often  corrosive  to  plants.  These 
salts  defiocculate  the  soil  and  injure  it  severely.  White  alkali  is  com- 
paratively easily  washed  out  of  the  soil  by  water,  but  black  alkali, 
owing  to  the  deflocculation  it  causes,  is  very  difficult  to  remove  by 
water  alone. 

4.  Is  it  Possible  to  Make  Black  Alkali  from  White  Alkali? 

To  some  extent,  this  conversion  may  be  brought  about  in  two  ways : 
(a)  When  water  containing  white  alkali  is  percolated  through  soil  con- 
taining much  calcium  carbonate,  some  sodium  carbonate  (black  alkali) 
may  be  formed.  (&)  If  the  soil  contains  no  calcium  carbonate,  water 
containing  white  alkali  percolating  through  it  may  so  change  the  com- 
position of  certain  of  the  mineral  constituents  that  when  the  soil  is 
leached  with  pure  water,  some  sodium  carbonate  may  be  produced. 
When  this  occurs  it  is  manifested  by  deflocculation  and  other  bad 
effects  known  to  be  caused  by  black  alkali.  In  either  case,  the  produc- 
tion of  sodium  carbonate  may  be  largely  or  entirely  prevented  by  the 
use  of  sufficient  gypsum.  This  may  be  applied  by  dissolving  it  in  the 
irrigating  water,  or  by  spreading  it  on  the  land  before  irrigating.  Since 
it  is  possible  to  produce  black  alkali  in  the  soil  by  leaching  out  white 
alkali,  it  is  very  important  to  avoid  adding  white  alkali  to  the  soil 
with  irrigating  water  or  in  any  other  way. 

5.  What  are  the  Effects  of  Alkali  on  Plants? 

Most  agricultural  plants  are  injured  by  large  amounts  of  any 
easily  soluble  salt  in  the  soil.  Much  of  the  harm  is  caused  by  the  effect 
of  the  salt  in  deranging  the  normal  water  relations  existing  between 
the  plant  and  the  soil.  Because  of  the  high  concentration  of  salts  in 
the  soil  moisture,  the  plant  cannot  obtain  its  normal  supply  of  water. 
Also,  it  is  possible  that  the  presence  of  sodium  salts  may  interfere  with 


*  The  finer  portions  of  most  normal  soils  are  united  into  groups  or  bundles 
or  crumbs,  often  spoken  of  as  fioccules.  When  the  soil  is  properly  managed 
these  fioccules  remain  intact.  Ordinary  cultivation  or  handling  does  not  break 
them  up.  If  the  soil  is  shaken  with  water,  worked  when  very  wet,  or  treated 
with  certain  chemicals,  such  as  black  alkali,  the  compound  bundles  or  fioccules 
are  broken  up  into  much  smaller  particles.  That  is,  the  soil  is  deflocculated,  or, 
as  a  farmer  mght  say,  the  soil  is  puddled.  Deflocculation  of  a  soil  is  very 
injurious  to  its  agricultural  value,  and  greatly  increases  the  difficulties  of  tillage. 
Deflocculation  greatly  decreases  the  rate  of  percolation  of  water  through  a  soil, 
makes  it  more  sticky  when  wet,  and  tends  to  produce  very  hard  clods  when 
the  soil  dries. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

the  normal  absorption  or  utilization  of  the  necessary  nutrients.  Thus, 
alkali  salts  sometimes  produce  difficulties  of  nutrition  in  plants,  even 
when  the  concentration  is  not  sufficient  to  disturb  seriously  the  water 
relations  referred  to. 

Black  alkali  acts  much  like  white  alkali  in  general,  but  also  produces 
certain  effects  peculiar  to  itself.  Small  amounts  may  change  the  com- 
position of  the  soil  moisture  so  that  plants  cannot  obtain  enough  iron, 
lime,  or  phosphorus,  to  maintain  healthy  growth.  Large  amounts  of 
black  alkali,  in  addition  to  the  harmful  effects  already  mentioned,  have 
a  corrosive  and  decomposing  action  on  the  bark  of  the  roots,  which 
may  destroy  the  plant.  Different  kinds  of  plants  differ  greatly  in  their 
ability  to  endure  the  evil  effects  of  alkali.  The  so-called  alkali  plants 
of  the  desert  live  in  the  presence  of  quantities  of  alkali  which  prevent 
the  growth  of  most  cultivated  plants. 

Alkali  injury  is  manifested  by  poor,  stunted,  or  abnormal  growth, 
drying  or  curling  up  of  leaves,  or  sometimes  yellowing,  mottling,  or 
other  discoloration,  or  loss  of  leaves.  New  growth  may  appear,  but 
soon  dies  away.  Some  of  these  effects  may  be  caused  by  lack  of  water, 
even  in  the  absence  of  alkali,  so  it  is  not  always  possible  to  tell  by  the 
appearance  whether  injury  to  a  plant  is  caused  by  alkali  or  by  lack 
of  water,  or  by  both. 

The  bad  effects  of  alkali  are  diminished  by  plenty  of  water,  so  that 
a  change  of  season  may  greatly  modify  the  effect. of  a  given  amount 
of  alkali  on  the  plant.  During  cool  weather,  the  plant  does  not  need 
so  much  water,  since  evaporation  from  leaf  surfaces  and  from  the  soil 
is  much  slower  when  the  air  is  cool  and  moist.  Therefore,  an  amount 
of  alkali  in  the  soil  which  would  be  very  injurious  in  summer,  may 
have  only  a  mildly  retarding  effect  on  the  plant  in  the  winter. 

6.  What  is  the  Effect  of  Alkali  on  the  Soil? 

Moderate  amounts  of  white  alkali  have  very  little  apparent  effect 
on  the  soil.  Large  amounts  cause  the  soil  to  swell  somewhat  and  to 
become  light  and  fluffy.  When  white  alkali  is  washed  out  of  the  soil, 
there  is  (as  already  mentioned  under  Section  4),  very  likely  to  be 
produced  a  small  amount  of  black  alkali  with  its  usual  bad  effects,  to 
be  described  below.  When  the  soil  contains  a  large  amount  of  salts, 
particularly  calcium  chloride  or  nitrate,  it  may  remain  permanently 
moist,  even  in  the  driest  part  of  the  summer.  Such  soils  are  sometimes 
mistaken  for  black  alkali  soils.  It  is  probabie  that  hardpan  is  often 
generated  by  the  action  of  alkali  in  combination  with  effects  produced 
by  the  movement  of  water  up  and  down  in  the  soil.  The  finer  the 
texture  of  the  soil — the  more  clay  it  contains — the  greater  are  the 
changes  produced  in  it  by  alkali. 


CIRC.  292]  ALKALI    SOILS  5 

Small  amounts  of  black  alkali  have  very  marked  effects  on  the  soil, 
causing  deflocculation  or  loss  of  crumb  structure  so  that  the  particles 
of  soil  approach  each  other  more  closely,  thus  producing  shrinkage 
which  may  cause  low  spots  in  the  field.  The  soil  becomes  much  more 
sticky  when  wet  and  much  less  easily  penetrated  by  water  when  dry. 
After  a  heavy  rain,  the  low  alkali  spots  remain  covered  with  water 
after  the  non-alkali  ground  is  dry.  When  black  alkali  soils  dry,  they 
bake  and  form  hard  clods.  Such  an  alkali  soil  is  likely  to  be  much 
more  difficult  to  till  than  the  same  soil  when  free  of  alkali.  Black  alkali 
prevents  iron  and  calcium  (and  phosphorus  under  some  circumstances) 
from  dissolving  in  the  soil  moisture  so  that  these  elements  may  become 
more  or  less  unavailable  to  plants,  and  growth  be  much  hindered. 

7.  How  May  the  Injurious  Effects  of  Alkali  on  Soil  be  Prevented? 

Use  only  good  water  for  irrigating.  Good  water  should  contain 
very  little  of  any  of  the  alkali  salts.  If  good  water  cannot  be  had,  it 
may  be  better  to  use  such  water  as  is  available,  rather  than  none,  but 
with  the  distinct  understanding  that  alkali  water  is  liable  to  ruin  the 
soil  eventually.  Avoid  using  an  excess  of  water.  Prevent  leakage  and 
seepage  from  canals  and  ditches.  Have  a  good  distributing  system 
so  that  the  water  is  evenly  applied  and  allowed  to  penetrate  uniformly 
all  over  the  field.  In  case  the  irrigating  water  contains  salts,  accumu- 
lation of  alkali  may  be  largely  prevented  by  flooding  the  land  once 
a  year  so  that  the  accumulated  salts  are  carried  away  in  the  drainage, 
down  into  the  ground  so  deep  that  none  will  return  to  the  surface 
again. 

In  all  cases  where  much  irrigation  water  is  used,  it  is  important  to 
have  some  adequate  means  of  drainage  which  will  prevent  the  rise  of 
the  water  table  too  near  to  the  surface.  The  distance  at  which  it 
becomes  dangerous  varies  with  the  character  of  the  soil.  If  it  comes 
close  to  the  top,  salts  are  likely  to  be  brought  to  the  surface  by  capil- 
lary action  and  thus  produce  an  alkali  crust  or  a  dangerous  concen- 
tration of  salts  in  the  region  of  plant  roots.  This  danger  was  pointed 
out  by  Hilgard  in  Bulletin  53  of  this  Station,  published  in  1886. 

The  production  of  harmful  concentrations  of  alkali  is  much  delayed 
by  any  means  which  reduces  evaporation  at  the  surface,  such  as  grow- 
ing crops  which  shade  the  soil,  growing  deep-rooting  crops  which  draw 
their  moisture  from  far  below  the  surface,  or  by  any  other  means 
which  keeps  the  alkali  distributed  through  a  large  body  of  soil,  instead 
of  allowing  it  to  concentrate  near  the  surface.  The  bad  effects  of  a 
small  amount  of  black  alkali  may  be  diminished,  or  sometimes  entirely 
avoided  by  the  use  of  gypsum,  sulfur,  or  other  chemicals.  Manure 
and  green  cover  crops  will  help  to  relieve  the  evil  if  the  soil  is  sup- 


6  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

plied  with  lime.  Decaying  vegetable  matter  helps  to  make  lime  soluble 
in  the  soil  moisture  so  that  plants  can  absorb  it,  and  it  can  act 
beneficially  on  the  soil. 

When  it  is  desired  to  start  sensitive  crops  on  alkali  soil,  the  surface 
crust  may  be  plowed  under,  thus  giving  the  young  plants  time  to  get  a 
start  before  the  alkali  again  comes  to  the  top.  A  better  procedure  is 
to  leach  the  salts  down  deeply  into  the  soil  by  heavy  irrigation  before 
seeding.  When  trees  are  planted,  they  are  helped  by  filling  in  around 
them  with  good  soil,  instead  of  the  alkali  soil  that  was  thrown  out  in 
digging  the  hole.  Any  kind  of  fertilizer  or  manure  that  enables  plants 
to  obtain  their  nutriment  more  easily  will  assist  in  reducing  the  bad 
effects  of  alkali. 

8.  How  Can  Alkali  be  Removed  from  the  Soil? 

First  cut  off  incoming  alkali,  by  proper  management  of  water 
supply  and  drainage.  Second,  discover,  if  possible,  the  kind,  amount 
and  location  of  the  alkali  as  a  basis  for  estimating  the  cost  of  reclama- 
tion. White  alkali  may  be  removed  by  flooding  with  good  water.  The 
presence  of  gypsum  or  lime  in  the  leaching  water  is  desirable  or  essen- 
tial in  order  to  avoid  formation  of  black  alkali  following  removal  of 
the  sodium  salts.  More  than  one  treatment  may  be  necessary.  Leach- 
ing out  in  this  way  requires  good  drainage.  Drainage  may  be 
improved  by  ditches,  tiling,  dynamiting  to  break  up  harclpan,  and  by 
sump  wells  into  which  the  water  may  flow.  The  drainage  question 
frequently  may  be  a  very  difficult  one  to  solve.  The  advice  of  a 
drainage  engineer  should  be  sought. 

Small  amounts  of  black  alkali  may  be  neutralized  by  addition  to 
the  soil  of  gypsum,  sulfur,  acids,  alum  or  of  some  other  chemicals, 
without  trying  to  leach  out  the  salts.  Large  amounts  of  black  alkali 
are  exceedingly  difficult  to  remove.  Years  of  patient  and  perhaps 
expensive  treatment  may  be  required.  The  economic  feasibility  of 
reclaiming  some  black  alkali  soils  has  yet  to  be  demonstrated. 

The  chemicals  just  mentioned  change  black  alkali  into  white  alkali. 
If  large  amounts  of  the  latter  are  present,  they  must  then  be  leached 
out  before  the  soil  will  become  suitable  for  crops.  In  consequence  of 
the  severe  leaching  required  to  remove  large  amounts  of  salts,  most 
of  the  soluble  plant  food  also  is  washed  away  with  the  alkali,  so  that 
a  leached  alkali  soil  is  likely  to  be  very  infertile.  This  may  make  it 
necessary  to  use  some  kind  of  fertilizer  to  get  a  crop  started.  After 
that,  the  fertility  of  the  land  may  be  gradually  restored  by  the  use  of 
green  manure  crops.  The  California  Experiment  Station  is  still 
investigating  alkali  problems,  and  in  many  cases  conclusive  recom- 
mendations must  await  the  outcome  of  further  experimentation. 


Cmc-  292J  ALKALI    SOILS  7 

9.  Importance  of  Preventing  Spread  of  Alkali. 

No  argument  is  necessary  to  show  that  it  is  better  to  prevent  the 
intrusion  of  alkali  than  to  try  to  remove  it  after  it  has  gotten  into 
the  soil.  Prevention  is  very  much  less  expensive  than  cure.  Great 
economic  loss  results  from  the  decreased  productivity  of  alkalied  land. 
As  just  stated,  reclamation  methods  are  not  yet  well  worked  out  and, 
besides,  are  very  expensive  in  both  time  and  money.  Public  officials, 
as  well  as  private  agencies,  should  do  all  in  their  power  to  prevent 
the  spread  of  alkali  into  good  land. 

10.  How  Much  Alkali  May  the  Soil  Contain  Without  Causing  Injury 

to  Crops? 

This  question  cannot  be  answered  definitely  or  precisely  for  the 
reason  that  conditions  other  than  the  amount  of  alkali  greatly  modify 
the  effect  of  the  alkali  itself.  Since  all  of  these  factors  vary  greatly 
from  time  to  time  and  are  little  subject  to  control  by  man,  manifestly 
it  is  possible  to  make  only  the  most  general  statement  as  to  how  much 
alkali  will  cause  trouble. 

Hilgard  has  stated  that  the  limits  of  tolerance  for  alkali  salts  are 
somewhat  as  follows : 

Sodium  carbonate  0.1%  to  0.25% 

Sodium  chloride  0.2%  to  0.50%,  and 

Sodium  sulfate  0.5%  to  1.00%  of  the  soil. 

Our  experience  is  that  much  smaller  amounts  may  be  very  injurious 
in  some  cases,  and  larger  amounts  may  cause  little  troube  in  other 
cases. 

The  limited  scope  of  the  present  treatment  permits  only  brief 
mention  of  the  principal  variable  factors  which  influence  the  effect 
of  alkali. 

(a)  The  kind  of  alkali.  The  relative  toxicity  of  the  several  salts 
has  often  been  found  to  be  approximately  that  indicated  above. 

(b)  The  location  of  the  alkali  in  the  soil,  whether  mostly  near  the 
top,  or  uniformly  distributed  through  the  zone  of  plant  roots,  or  little 
at  the  top  and  in  greater  concentration  lower  down,  will  greatly 
modify  its  effects  on  the  plant,  according  to  its  habits  of  growth  and 
the  character  of  its  rooting  system,  whether  deep  or  shallow,  etc. 

(c)  The  physical  character  of  the  soil,  whether  sand,  silt,  loam, 
clay,  or  peat,  materially  changes  the  effect  of  a  given  amount  of  alkali. 
The  more  sand  there  is  in  a  soil  the  more  injurious  to  plants  is  the 
effect  of  a  given  amount  of  alkali,  and  the  less  the  apparent  change  in 
the  physical  condition  of  the  soil.     On  the  other  hand  the  greater  the 


8  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

amount  of  clay  in  a  soil,  the  less  harmful  to  plants  is  a  given  amount 
of  alkali,  but  the  greater  is  the  injury  to  the  physical  character  of  the 
soil.  When  clay  contains  much  black  alkali,  ordinary  tillage  may  be 
very  difficult,  perhaps  impossible.  A  large  amount  of  organic  matter 
such  as  is  contained  in  a  peat  soil,  greatly  reduces  the  harmful  effects 
of  salts  on  plants  growing  in  the  soil. 

(d)  The  natural  fertility  of  the  soil  itself  apart  from  alkali  may 
make  much  difference.  The  more  fertile  the  soil,  the  better  will  plants 
endure  the  harmful  effects  of  alkali.  A  liberal  use  of  fertilizers  may 
permit  production  of  a  good  crop  on  soil  containing  so  much  salts  that 
without  the  fertilizer,  little  could  be  grown.  These  are  only  general 
observations.  It  should  not  be  assumed  that  the  addition  of  fertilizers 
will  prevent  alkali  injury. 

(e)  The  amount  and  timeliness  of  the  moisture  supply  in  the  soil 
is  very  important  in  respect  to  alkali.  The  more  moisture  in  the  soil, 
the  lower  will  be  the  concentration  of  alkali  in  the  soil  moisture  and 
the  less  harm  will  the  alkali  do.  This  implies  that  the  supply  of 
moisture  must  be  kept  up,  for  if  the  ground  should  become  very  dry, 
the  concentration  of  alkali  in  the  soil  moisture  might  become  great 
enough  to  injure  the  plants. 

(/)  Climate  and  season  of  the  year  in  relation  to  the  growth  period 
of  the  crop  will  influence  the  results  materially.  It  has  been  found 
that  an  amount  of  salt  which  was  very  injurious  to  wheat  in  the 
summer  time,  did  little  harm  in  the  cooler  weather  of  winter.  This 
is  partly  because  alkali  is  brought  to  the  surface  by  capillarity  (with 
evaporation  of  water),  while  in  winter  it  is  washed  down  by  rains  into 
lower  depths,  and  also  because  crops  suffer  greater  injury  from  alkali 
in  hot,  dry  weather  than  in  cool  moist  weather,  as  already  stated  in 
Section  (e). 

(g)  Most  important  of  all  is  the  tolerance  of  the  plant  itself.  This 
subject  is  considered  in  the  next  section. 

11.  What  is  the  Tolerance  of  Various  Crops  for  Alkali? 

As  stated  in  more  detail  in  the  preceding  section,  the  capacity  of 
any  plant  to  endure  alkali  varies  greatly  with  the  physical  character 
of  the  soil,  whether  sand,  loam,  clay,  or  peat,  with  the  kind,  amount 
and  location  of  the  alkali,  with  the  fertility  of  the  soil,  with  the  water 
supply,  the  climate  and  other  factors.  Consequetly,  it  is  not  possible 
to  indicate  the  tolerance  of  any  plant,  except  in  a  very  general  way. 
Even  in  any  one  species  of  plants,  some  varieties  are  much  more 
tolerant  than  others. 


ClRC  292]  ALKALI    SOILS  9 

In  considering  what  is  likely  to  be  the  most  successful  crop  on 
alkali  soil,  or  whether  any  particular  crop  will  clo  well,  attention  to 
the  following  points  is  important : 

How  will  the  alkali  affect  germination  of  the  seed?  Germination 
may  be  delayed  or  prevented  by  alkali. 

Will  the  young  seedlings  be  injured  ?  Most  young  plants  are  very 
sensitive  and  easily  injured. 

Can  proper  moisture  conditions  be  maintained  during  germination 
and  the  seedling  stage?  If  the  soil  becomes  dry,  the  alkali  is  more 
likely  to  injure  plants. 

Is  the  mature  plant  resistant  to  alkali  ?  Some  plants,  for  example, 
alfalfa,  are  very  sensitive  in  the  seedling  stage,  but  can  endure  a 
good  deal  wnen  fairly  mature. 

Is  the  root  system  of  the  plant  adapted  to  the  particular  conditions 
of  the  soil,  moisture  and  alkali  in  this  place?  [See  (b)  under  Section 
10,  p.  7.] 

How  will  the  plant  be  affected  by  flooding  or  other  conditions  which 
may  be  incidental  to  reclamation  procedures  ?  Some  plants  can  endure 
standing  water  for  many  hours,  others  are  quickly  injured  if  the  soil  is 
covered  with  water. 

Can  tillage  be  managed  so  that  there  will  be  little  tendency  to 
cause  rise  of  alkali  to  the  top  of  the  soil  where  it  is  most  harmful  ? 
This  last  is  to  be  considered  in  connection  with  the  fact  that  for  most 
plants  the  alkali  is  likely  to  be  less  injurious  if  it  can  be  kept  distri- 
buted through  the  whole  body  of  the  soil,  than  if  allowed  to  concentrate 
near  the  surface. 

In  general,  the  grasses,  which  include  all  our  cultivated  grains,  are 
more  resistant  to  alkali  than  most  crops,  though  bluegrass  and  some 
other  grasses  are  very  sensitive  to  alkali.  Wheat,  barley,  and  milo 
endure  alkali  better  than  corn.  Bermuda  grass  and  Rhodes  grass  are 
exceptionally  tolerant  of  black  alkali. 

The  legumes  are  generally  rather  sensitive  to  alkali,  with  some 
marked  exceptions.  Alfalfa,  when  old,  will  endure  a  good  deal,  so  will 
melilotus  (sweet  clover)  and  hairy  vetch.  Beans  and  peas  are  easily 
injured.  Root  crops  like  beets  and  onions  are  quite  tolerant  of  alkali. 
Melons  are  very  sensitive.  Most  fruit  trees  arc  easily  injured.  General 
observations  in  the  field  indicate  that  walnut  and  citrus  trees  are  most 
sensitive,  next  come  apples,  apricots,  plums,  prunes,  peaches,  pears 
and  grapes,  while  olives  are  most  tolerant  of  alkali.  This  order  of 
relative  resistance  to  alkali  will  vary  in  different  soils  and  with 
different  kinds  or  combinations  of  alkali. 


10  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

12.  Is  Alkali  Uniformly  Distributed  in  the  Soil? 

Any  one  who  has  had  experience  with  alkali  knows  that  it  is 
exceedingly  variable.  " Alkali  spots"  in  fields  are  commonly  known 
as  areas  where  so  much  alkali  is  present  that  there  is  very  poor  or  no 
growth  of  plants.  A  little  thought  should  convince  one  that  since 
there  is  evident  variation  in  amount  of  alkali  between  the  good  soil 
and  the  alkali  spots,  that  there  is  likely  to  be  variation  between  other 
places  although  they  may  appear  similar  to  the  eye.  But  if  one  may 
judge  from  the  inquiries  that  are  frequently  received  at  the  experi- 
ment station,  many  persons  do  not  realize  the  enormous  difference  in 
the  amount  of  alkali  present  in  spots  often  very  close  together. 
Actually  the  amount  may  be  5  or  10  times  as  much  in  one  place  as  in 
another,  only  one  or  two  feet  distant.  It  is  on  account  of  this  great 
variability  that  it  is  so  difficult  to  find  out  how  much  alkali  there  is 
in  any  certain  field,  and  also  the  tolerance  of  crops  for  alkali.  Some 
of  the  causes  of  this  variability  in  distribution  of  alkali  are :  physical 
inequalities  in  the  soil,  and  changes  caused  by  movement  of  water, 
growth  of  crops,  and  tillage.  The  salts  in  the  soil  are  constantly  being 
moved  about,  up  or  down,  or  horizontally,  by  the  changes  in  amount 
and  location  of  the  soil  moisture,  induced  by  rain,  irrigation,  rise  or 
fall  of  the  water  table,  if  near  the  surface,  and  withdrawal  of  moisture 
by  growing  crops.  In  these  movements  caused  by  changes  in  position 
of  the  soil  moisture,  some  of  the  salts  are  moved  through  the  soil 
faster  than  others.  Thus  some  of  the  inequalities  in  distribution  of 
alkali  are  produced.  On  account  of  these  great  variations  in  alkali 
content,  a  single  sample  or  even  several  samples  of  soil  from  any  field 
cannot  be  expected  to  give  a  correct  idea  of  the  actual  amount  of  salts 
in  the  soil  of  the  whole  field,  or  indicate  precisely  how  any  particular 
crop  on  the  land  would  be  affected  by  the  salts  present.  Only  by 
taking  a  great  number  of  samples,  each  to  be  tested  separately,  or 
possibly  after  being  composited,  can  the  alkali  content  of  any  field  be 
determined  with  even  approximate  accuracy.  This  is  too  expensive 
for  any  ordinary  practical  purpose. 

13.  What  Value  has  a  Chemical  Analysis  of  Alkali  Soils f 
Considering  that  there  is  such  great  variation  in  alkali  soil,  it  may 

appear  futile  to  make  a  chemical  analysis  of  the  soil  for  the  purpose  of 
determining  the  amount  of  alkali  in  any  one  spot.  This  would  be  true 
if  it  were  necessary  to  know  with  approximate  accuracy  the  amount 
and  kind  of  salts  present  in  the  whole  field.  But  this  is  not  necessary 
in  order  to  decide  upon  a  general  treatment  of  the  soil  for  removal  of 
the  alkali,  or  to  select  a  suitable  crop  to  be  grown.     If  the  analysis 


CIRC.  292]  ALKALI   SOILS  11 

shows  no  alkali  in  the  sample  examined,  this  should  be  regarded  as 
only  a  general  indication.  Alkali  might  be  present  to  an  injurious 
extent  in  other  portions  of  the  field.  But  if  some  alkali  is  found  in 
the  sample  examined,  it  is  quite  possible  that  there  is  enough  present 
in  many  places  in  the  field  to  make  trouble.  The  presence  of  alkali  in 
any  sample  is  a  cause  for  suspicion  so  that  it  may  become  advisable  to 
test  other  samples  from  many  places  in  order  to  obtain  a  better  repre- 
sentation of  the  whole  area.  This  is  expensive,  but  necessary  if  reason- 
able certainty  is  desired.  Instead  of  taking  so  many  sample-;,  it  may 
be  taken  for  granted,  on  the  basis  of  the  results  obtained  from  a  few 
samples  that  either  (a)  there  is  no  alkali  in  the  soil,  or,  (b)  if  alkali 
is  found,  suitable  treatment  may  be  recommended.  This  is  the  usual 
custom.  In  any  case,  the  treatment  is  applied  uniformly  so  that  some 
spots  receive  unnecessary  attention  and  others  are  inadequately 
treated.  After  some  time,  other  tests  may  be  made  on  samples  taken 
from  as  nearly  as  possible  the  same  spots,  to  learn  whether  the  desired 
effects  are  being  produced.  The  growth  of  crops  will  also  serve  to 
indicate  which  spots  require  further  treatment. 

Chemical  tests  are  valuable  to  show  whether  alkali  is  present,  and 
if  so,  what  kind,  and  to  suggest  means  of  removing  it,  even  though 
the  sample  examined  does  not  truly  represent  the  whole  area.  If  no 
alkali  is  found,  it  is  in  order  to  seek  some  other  cause  for  the  failure 
of  crops  on  the  land. 

14.  What  is  the  Proper  Way  to  Take  Soil  Samples  to  be  Tested  for 
Alkali? 

Before  taking  samples  of  soil,  or  sending  them  to  be  tested,  the 
inquirer  should  try  to  decide  whether  any  test  or  analysis  is  needed, 
whether  a  test  can  answer  the  question  he  has  in  mind,  or  indicate  how 
the  soil  should  be  treated.  In  making  this  decision  the  farm  advisor 
should  be  consulted. 

If  there  is  a  good  growth  of  vegetation,  or  any  kind  of  successful 
crop  on  the  land,  it  would  be  a  waste  of  time  to  make  tests  for  alkali, 
for  there  is  evidently  not  enough  to  do  much  harm.  If  it  is  already 
known  from  observation  or  experience  that  the  soil  contains  alkali,  no 
test  is  needed  to  show  its  presence,  although  a  test  may  be  desirable  to 
indicate  the  best  method  for  reclamation.  There  is  no  use  in  having 
an  analysis  of  soil  made  for  the  purpose  of  determining  crop  adapta- 
tion or  fertilizer  requirements.  It  is  not  yet  possible  to  predict  from 
the  results  of  a  soil  analysis  what  crops  will  do  well  on  the  land,  or 
what  fertilizer,  if  any,  will  produce  the  most  benefit.  Such  practical 
questions  can  best  be  answered  by  a  knowledge  of  the  general  condi- 


12  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

tions  of  the  locality.  Find  out  what  is  growing  well  on  similar  soil 
nearby.  If  a  certain  crop  is  a  failure  on  one  piece  of  land,  it  may  fail 
on  other  similar  neighboring  land  similarly  managed.  Whether  any 
fertilizer  is  needed  or  will  pay  must  be  found  out  by  actual  trials  in 
the  field  and  by  careful  consideration  of  the  cost  of  production  in 
relation  to  market  prices.  The  advice  of  one  who  knows  the  country, 
namely  the  farm  advisor,  is  most  useful  in  answering  all  these 
questions. 

The  following  instructions  are  intended  particularly  for  those  cases 
where  it  is  desired  to  determine  the  presence  or  absence  of  alkali  by 
taking  one  or  a  few  samples,  but  not  for  the  purpose  of  an  alkali 
survey. 

15.  Instructions  for  Taking  Samples  to  he  Tested. 

Select  a  spot  where  alkali  is  most  likely  to  be  found.  If  there  is 
any  surface  crust  apparent,  take  a  sample  and  mark  it  "surface." 
Bore  down  with  a  soil  auger  one  foot.  Collect  the  borings  on  a  piece 
of  canvas  or  oil  cloth  and  mix  well.  Of  this  mixture,  take  a  portion 
of  %  to  1  pound  and  mark  the  sample  "Hole  1,  first  foot."  Now  bore 
down  to  the  bottom  of  the  second  foot,  mix  the  boring,  take  a  sample  as 
before  and  mark  it  "Hole  1,  second  foot."  Continue  with  the  third 
and  fourth  feet  in  similar  manner.  An  excellent  method  of  marking 
the  samples  is  as  follows  :  Instead  of  writing  "Hole  1,  first  foot,  second 
foot,"  etc.,  write  simply  1.1,  1.2,  1.3,  1.4,  on  the  samples  from  the 
first  hole,  then  2.1,  2.2,  2.3,  and  2.4,  on  samples  from  the  second  hole, 
etc.  The  samples  are  most  conveniently  kept  in  stout  paper  bags  which 
are  easily  marked.  If  the  soil  is  moist,  it  should  be  dried  before  the 
samples  are  packed  for  shipping,  in  order  to  avoid  breakage  of 
packages  and  loss  of  samples. 

Samples  thus  properly  taken  from  a  few  holes  in  well  selected 
places,  should  give  a  very  good  idea  of  the  land  in  respect  to  alkali. 
But  if  only  a  few  lumps  of  soil  from  the  surface  are  taken,  it  is  hardly 
worth  while  to  test  them.  Such  grab  samples  cannot  be  considered  to 
represent  anything  but  themselves.  To  base  a  decision  as  to  the 
condition  of  a  piece  of  land  on  the  results  of  an  examination  of  one 
or  two  surface  samples,  is  scarcely  better  than  guessing  at  it.  The 
condition  of  the  soil  to  at  least  four  feet  in  depth  should  be  determined 
in  more  than  one  place.  An  alkali  survey  to  ascertain  quite  accurately 
the  amount  and  kind  of  alkali  in  a  piece  of  land  requires  systematic 
sampling  in  many  places.  This  is  quite  expensive  and  probably  not 
necessary  for  most  practical  purposes. 


CiRC.  292]  ALKALI   SOILS  13 

Any  one  who  desires  assistance  or  advice  in  regard  to  soil  problems 
should  first  consult  the  county  farm  advisor.  He  may  be  able  to  settle 
the  question  without  going  further.  But  if  he  cannot  give  the  desired 
information,  he  will  direct  the  inquirer  how  to  proceed  to  obtain  any 
available  information  on  the  subject.  The  name  and  address  of  the 
farm  advisor  for  any  particular  county  may  be  obtained  upon  request 
from  the  Division  of  Agricultural  Extension,  University  of  California, 
Berkeley,  California. 

If  samples  of  soil  are  sent  to  be  tested,  a  letter  should  be  sent 
at  the  same  time,  but  separately  from  the  samples,  with  full  informa- 
tion on  the  following  points : 

Sent  by  Address 

From  Ranch  of Date  sent 

Mark  on  samples  

Location  of  land Sec Township Range 

Topography  of  land:  Level,  rolling,  hilly,  swampy 

Physical  character  of  soils:  Sand,  fine  sand,  silt,  silt  loam,  clay  loam,  adobe,  clay, 

muck,  peat,  hardpan  at  feet  depth,  calcareous 

Area:  How  many  acres,  approximately  

Drainage:  Is  the  ground  level,  or  sloping,  underlaid  by  gravel,  sand  or  clay? 

Water  table:  How  far  below  surface?  

Irrigation  water:  From  river,  lake,  spring,  well.     Is  it 

abundant  or  scarce?  What  is  its  quality,  good, 

saline,  alkaline?  

Crops  now,  or  recently  growing:  

Crop  desired  to  produce :  

Character  of  suspected  troulle:  Alkali,  salts,  acidity  

Is  the  sample  average,  or  better,  or  worse  than  the  average  of  the  field  ■ 

Remarks  (Add  here  other  pertinent  information):  


14  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

Importance  of  Proper  Packing. — Packages  containing  soil  enclosed 
in  thin  paper,  thin  paper  bags  or  other  flimsy  materials  are  liable  to 
be  broken  in  transit  so  that  the  samples  are  mixed  or  lost.  Metal  or 
wooden  boxes,  stout  cloth  sacks,  or  strong  paper  bags  if  packed  in  boxes 
or  heavy  paper,  are  suitable  containers  for  soil  samples.  The  soil 
should  be  dry  before  it  is  packed. 

Importance  of  Labelling. — Good  labelling  is  as  important  as  ade- 
quate sampling,  therefore,  be  sure  that  the  writing  on  the  labels  is 
distinct  and  permanent.  Indistinct,  or  otherwise  inadequate,  marking 
often  causes  difficulty  in  giving  a  satisfactory  report.  Mark  each 
sample  plainly.  The  address  of  the  sender  should  be  placed  on  the 
outside  of  the  package. 


STATION  PUBLICATIONS  AVAILABLE  FOR  FREE  DISTRIBUTION 


BULLETINS 

No. 

the 

353. 

ia. 

354. 

ans 

357. 

No. 

253.   Irrigation   and   Soil  Conditions   in 
Sierra  Nevada  Foothills,  Californ 

261.  Melaxuma    of    the    Walnut,     "Jug] 

regia." 

262.  Citrus  Diseases  of  Florida   and   Cuba 

Compared  with  Those  of  California.  358. 

263.  Size  Grades  for  Ripe  Olives. 

268.   Growing  and  Grafting  Olive  Seedlings.  359. 

273.   Preliminary  Report  on  Kearney  Vine-  361. 

yard  Experimental  Drain. 

275.  The  Cultivation  of  Belladonna  in  Cali-  362. 

fornia.  363. 

276.  The  Pomegranate. 

277.  Sudan  Grass  364. 

278.  Grain   Sorghums. 

279.  Irrigation  of  Rice  in  California.  365. 

280.  Irrigation  of  Alfalfa  in  the  Sacramento  366. 

Valley. 
283.  The  Olive  Insects  of  California.  367. 

285.  The  Milk  Goat  in  California. 

286.  Commercial  Fertilizers.  368. 
294.   Bean  Culture  in  California. 

304.  A   Study  of  the  Effects  of  Freezes  on  369. 

Citrus   in   California.  370. 

310.   Plum  Pollination.  371. 

312.  Mariout  Barley. 

313.  Pruning  Young  Deciduous  Fruit  Trees.  372. 
319.   Caprifigs  and  Caprification. 

324.  Storage  of  Perishable  Fruit  at  Freezing  374. 

Temperatures. 

325.  Rice  Irrigation  Measurements  and  Ex- 

periments    in     Sacramento     Valley,  375. 

1914-1919. 
328.  Prune  Growing  in  California.  376. 

331.  Phylloxera-Resistant  Stocks. 

334.  Preliminary  Volume  Tables  for  Second-  377. 

Growth  Redwood.  379. 

335.  Cocoanut   Meal   as   a   Feed  for  Dairy  380. 

Cows  and  Other  Livestock. 

339.  The  Relative  Cost  of  Making  Logs  from  381. 

Small  and  Large  Timber. 

340.  Control  of  the  Pocket  Gopher  in  Cali-  382. 

fornia. 

343.  Cheese  Pests  and  Their  Control.  383. 

344.  Cold  Storage  as  an  Aid  to  the  Market- 

ing of  Plums.  384. 

346.  Almond  Pollination. 

347.  The  Control  of  Red  Spiders  in  Decidu- 

ous Orchards.  385. 

348.  Pruning  Young  Olive  Trees.  386. 

349.  A    Study    of    Sidedraft    and    Tractor 

Hitches.  387. 

350.  Agriculture  in  Cut-over  Redwood  Lands. 
352.  Further  Experiments  in  Plum  Pollina- 
tion. 


Bovine  Infectious  Abortion. 

Results  of  Rice  Experiments  in   1922. 

A  Self-mixing  Dusting  Machine  for 
Applying  Dry  Insecticides  and 
P'ungicides. 

Black  Measles,  Water  Berries,  and 
Related  Vine  Troubles. 

Fruit  Beverage  Investigations. 

Preliminary  Yield  Tables  for  Second 
Growth  Redwood. 

Dust  and  the  Tractor  Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Avocado   Culture   in   California. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in  Relation  to  Mouldy  Walnuts. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter  Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and  Large  Timber. 

The  Cost  of  Producing  Market  Milk  and 
Butterfat  on  246  California  Dairies. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,    1923. 

Sun-Drying  and  Dehydration  of  Wal- 
nuts. 

The  Cold  Storage  of  Pears. 

Walnut  Culture  in  California. 

Growth  of  Eucalyptus  in  California 
Plantations. 

Growing  and  Handling  Asparagus 
Crowns. 

Pumping  for  Drainage  in  the  San 
Joaquin  Valley,   California. 

Monilia  Blossom  Blight  (Brown  Rot) 
of  Apricot. 

A  Study  of  the  Relative  Values  of  Cer- 
tain Succulent  Feeds  and  Alfalfa  Meal 
as  Sourses  of  Vitamin  A  for  Poultry. 

Pollination  of  the  Sweet  Cherry. 

Pruning  Bearing  Deciduous  Fruit 
Trees. 

Fig  Smut. 


CIRCULARS 


No. 

87.   Alfalfa. 
113.  Correspondence  Courses  in  Agriculture. 
117.  The    Selection    and    Cost    of    a    Small 

Pumping  Plant. 
127.  House  Fumigation. 
129.  The  Control  of  Citrus  Insects. 
136.  Ifelilotus    indica    as    a    Green-Manure 

Crop  for  California. 
144.    Oidium  or  Powdery  Mildew  of  the  Vine. 

151.  Feeding  and  Management  of  Hogs. 

152.  Some  Observations  on  the  Bulk  Hand- 

ling of  Grain   in  California. 

154.  Irrigation   Practice   in   Growing  Small 

Fruit  in  California. 

155.  Bovine  Tuberculosis. 


No. 

157. 

160. 

164. 

165. 


Control  of  the  Pear  Scab. 
Lettuce  Growing  in  California. 
Small  Fruit  Culture  in  California. 
Fundamentals   of   Sugar    Beet   Culture 
under  California  Conditions. 

166.  The  County  Farm  Bureau. 

167.  Feeding  Stuffs  of  Minor  Importance. 
170.   Fertilizing  California  Soils  for  the  1918 

Crop. 
173.  The    Construction    of   the   Wood-Hoop 
Silo. 

178.  The  Packing  of  Apples  in  California. 

179.  Factors    of    Importance    in    Producing 

Milk  of  Low  Bacterial  Count. 
184.  A  Flock  of  Sheep  on  the  Farm. 


CIRCULARS—  (Continued) 


No.  No. 

190.  Agriculture  Clubs  in  California.  252. 

199.   Onion  Growing  in  California.  253. 

202.  County   Organizations   for   Rural   Fire  254. 

Control. 

203.  Peat  as  a  Manure  Substitute.  255. 

208.  Summary  of  the  Annual  Reports  of  the 

Farm  Advisors  of  California.  256. 

209.  The  Function  of  the  Farm  Bureau.  257. 

210.  Suggestions  to  the  Settler  in  California.  258. 
212.   Salvaging  Rain-Damaged  Prunes.  259. 

214.  Seed  Treatment  for  the  Prevention  of  260. 

Cereal  Smuts. 

215.  Feeding  Dairy  Cows  in  California.  261. 
217.   Methods   for   Marketing  Vegetables   in  262. 

California.  263. 

220.   Unfermented  Fruit  Juices.  264. 

228.   Vineyard  Irrigation   in  Arid  Climates. 

230.  Testing   Milk,    Cream,    and   Skim   Milk  265. 

for   Butterfat.  266. 

231.  The  Home  Vineyard. 

232.  Harvesting    and    Handling    California  267. 

Cherries  for  Eastern   Shipment. 

233.  Artificial  Incubation.  268. 

234.  Winter  Injury  to  Young  Walnut  Trees 

during  1921-22.  269. 

235.  Soil  Analysis  and  Soil  and  Plant  Inter-  270. 
relations.                                                                      271. 

236.  The  Common  Hawks  and  Owls  of  Cali-  272. 

fornia    from    the    Standpoint    of    the 

Rancher.  273. 

237.  Directions  for  the  Tanning  and  Dress-  274. 

of  Furs. 

238.  The  Apricot  in  California.  275. 

239.  Harvesting  and  Handling  Apricots  and 

Plums  for  Eastern  Shipment.  276. 

240.  Harvesting    and    Handling    Pears    for  277. 

Eastern  Shipment. 

241.  Harvesting  and  Handling  Peaches  for  278. 

Eastern   Shipment. 

242.  Poultry   Feeding.  279. 

243.  Marmalade  Juice  and  Jelly  Juice  from 

Citrus  Fruits.  281. 

244.  Central  Wire  Bracing  for  Fruit  Trees. 

245.  Vine  Pruning  Systems. 

247.  Colonization  and  Rural  Development.  282. 

248.  Some  Common  Errors  in  Vine  Pruning 

and  Their  Remedies.  283. 

249.  Replacing  Missing  Vines.  284. 

250.  Measurement   of   Irrigation   Water   on  289. 

the  Farm. 

251.  Recommendations  Concerning  the  Com- 

mon    Diseases     and     Parasites     of 
Poultry  in  California. 


Supports  for  Vines. 

Vineyard  Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter  Egg  Production. 

Leguminous  Plants  as  Organic  Fertil- 
izer in   California  Agriculture. 

The  Control  of  Wild  Morning  Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning  Deciduous  Fruits. 

Pear  By-products. 

A  Selected  List  of  References  Relating 
to  Irrigation  in  California. 

Sewing  Grain   Sacks. 

Cabbage  Growing  in  California. 

Tomato  Production  in  California. 

Preliminary  Essentials  to  Bovine  Tuber- 
culosis Control. 

Plant  Disease  and  Pest  Control. 

Analyzing  the  Citrus  Orchard  by  Means 
of  Simple  Tree  Records. 

The  Tendency  of  Tractors  to  Rise  in 
Front;  Causes  and  Remedies. 

Inexpensive  Lavor-saving  Poultry  Ap- 
pliances. 

An  Orchard  Brush  Burner. 

A  Farm  Septic  Tank. 

Brooding  Chicks  Artificially. 

California  Farm  Tenancy  and  Methods 
of  Leasing. 

Saving  the  Gophered  Citrus  Tree. 

Fusarium  Wilt  of  Tomato  and  its  Con- 
trol by  Means  of  Resistant  Varieties. 

Marketable  California  Decorative 
Greens. 

Home  Canning. 

Head,  Cane,  and  Cordon  Pruning  of 
Vines. 

Olive  Pickling  in  Mediterranean  Coun- 
tries. 

The  Preparation  and  Refining  of  Olive 
Oil  in  Southern  Europe. 

The  Results  of  a  Survey  to  Determine 
the  Cost  of  Producing  Beef  in  Cali- 
fornia. 

Prevention  of  Insect  Attack  on  Stored 
Grain. 

Fertilizing  Citrus  Trees  in  California. 

The  Almond  in  California. 

Oak  Fungus  in  Orchard  Trees. 


The  publications  listed  above  may  be  had  by  addressing 

College  of  Agriculture, 

University  of  California, 

Berkeley,  California. 


15m-6,*25 


